National Parks/Monuments
Tribal BoundariesThe tribal boundaries shown here are provided by the Bureau of Indian Affairs
and are intended to be used as a general spatial reference only. They are not a formal
determination of tribal boundaries by the EPA.

National Parks/Monuments
Tribal BoundariesThe tribal boundaries shown here are provided by the Bureau of Indian Affairs
and are intended to be used as a general spatial reference only. They are not a formal
determination of tribal boundaries by the EPA.

National Parks/Monuments
Tribal BoundariesThe tribal boundaries shown here are provided by the Bureau of Indian Affairs
and are intended to be used as a general spatial reference only. They are not a formal
determination of tribal boundaries by the EPA.

AQI: Good (0 - 50)
Air quality is considered satisfactory, and air pollution poses little or no risk.

AQI: Moderate (51 - 100)
Air quality is acceptable; however, for some pollutants there may be a moderate health concern for a very small number of people who are unusually sensitive to air pollution.

AQI: Unhealthy for Sensitive Groups (101 - 150)
Although general public is not likely to be affected at this AQI range, people with lung disease, older adults and children are at a greater risk from exposure to ozone, whereas persons with heart and lung disease, older adults and children are at greater risk from the presence of particles in the air.

Forecast Discussion: December 6 to 11 – A cold and dry air mass remains in place into Wednesday when air with a more subtropical origin moves in, resulting in milder temperatures. This shift will also usher in a pattern change which will deliver unsettled weather with on and off rainfall likely into the weekend. This progressive pattern should keep air pollution from building up with GOOD air quality persisting over most parts of the region. However, on Tuesday night overnight temperatures in the San Lorenzo Valley will dip into the low 30’s with frost likely. This will prompt increased residential wood burning causing air quality for PM2.5 to reach the MODERATE category of EPA’s Air quality Index (AQI) with possible overnight excursions into the UNHEALTHY FOR SENSITIVE GROUPS. However, no exceedances of EPA’s air quality standard for PM2.5 are expected at this time.

Current Conditions

Air Quality Index (AQI)observed at 16:00 PST

25

Good

Health Message: None

Note: Values above 500 are considered Beyond the AQI. Follow recommendations for the Hazardous category. Additional information on reducing exposure to extremely high levels of particle pollution is available here.